Door closer



April 18, 1961 A. S. KATZ DOOR CLOSER Filed Dec. 29, 1958 INVENTOR.

A VRUM .5. KA TZ ATTORA/f) 2,979,759 t ..l .s. t A 8; .95.

Ueit d, Stat s Paten DOOR CLOSER Avrum S. Katz, Cleveland, Ohio,assignor to Sterling Industries, Inc., Cleveland, Ohio, a corporation ofOhio Filed Dec. 29, 1958, Ser. No. 783,302

2 Claims. (Cl. 16-66) the like and particularly to door closers whichemploy a compression spring which is loaded by opening of a door withwhich the device is associated and which also includes a fluid meteringdevice. which smoothly accommodates and controls return of the spring toits relatively uncompressed condition.

. As used herein the term compression spring door closer-means a doorcloser of the above type and of contemporary refined design in which thespring has those characteristics which are consistent with applicabledesign criteria, including necessary operating characteristics, exteriordimension limitations, and spring de sign considerations. Morespecifically, the term compression spring door closer pertains to doorclosers having a ratio of overall free length to mean spring diameter offrom 12 to 20 and having a spring rate of .2 to 5 pounds per inch ofdeflection and having a desired optimum load (at a compressed length offrom 6 to 10 inches) of from 10 to 25 pounds. This load is referred toas the latching load and is that load which obtains just prior tocompletion of expansion of the spring with in the door closer housing,as upon closing of an associated door latch.

The latching loads of compression spring door closers of the prior artvary considerably in successive opera tions of each individual closer.An object of the present invention is to provide a door closer havingimproved constancy of latching load. The desired optimum latching loadof a compression spring door closer may be chosen within fairly widelimits as indicated in the preceding paragraph, depending on the doordimensions and interrelation of the door closer and the door. Howeveronce the optimum latching load is chosen according to the aboveconsiderations, then it is important that such chosen latching load beachieved as constantly as possible in successive operations of eachindividual door closer. The more constant the latching load, the widerthe variation in installation conditions which can be successfully metby the door closer. The installation conditions may include cases wherethe door closer and its accompanying door are installed as a screen dooror the: like where there is substantially no latch resistance and no airentrapment and therefore no cushioning during final closing of the door.On the other hand, the door may be. installed with weather stripping ina door frame with a second interior or permanent door so that when thedoor in question is closed a considerable cushioningeffeet isencountered as the air trapped behind the door becomes slightlypressurized over the wide area of the doors expanse. This resistance maybe augmented by a still latch. ObviouSlythere are. extremes in eitherdirection beyond which the door closer cannot be expected to functionsatisfactorily, but the effect of increasing the constancy of thelatchingload of the door closer. is to 2 vention will therefore cover awider range of conditions than previous door closers.

I have discovered that the constancy of latching load in compressionspring door closers may be significantly improved by dividing the doorcloser spring into not less than three sections. While it would notappear that de-v vices in which the spring load varied from say 20pounds at latch loading condition up to say 36 pounds at door opencondition could be significantly improved as to constancy by renderingthe spring less uniform, this is nevertheless the result achieved by thepresent invention in the case of door closer springs having thecharacteristics expressly connoted by the term compression spring doorclosers as defined above. It may be noted that in such cases theprovision of a double spring section effects no substantial improvementover a single spring and may actually result in inferior operation. Itis the triple spring section that accomplishes the improved results.

The drawing is a sectional view of a door closer embodying theinvention.

The drawing shows a door closer which in some respects is similar toconventional closers. When the associated door is opened, the shaft 14is extended and the plunger comprising the elements 1 and 5 is moved inthe rightward direction asthe parts are viewed in the figure. When thedoor is released; the spring means 7, 9, 11 returns the door to theclosed position, the plunger 1, 5 acting to limit the return movement orexpansion of the spring so that the closing action will be smooth. Thelatching force exerted by the spring is that force exerted just beforethe spring fully expands to the condition illustrated in the drawing.Limiting of the speed of movement of the plunger 1, 5 is accomplishedthrough metering of air or hydraulic liquid. Where air metering is used,it may be accomplished through an appropriate exterior metering orifice,such as the adjustable orifice 10, which limits the ejection of air fromthe chamber on the left-hand side of the plunger 1, 5 to the exterioratmosphere. Where liquid metering is employed, a metering arrangement isprovided to allow liquid to flow freely from the right to the left ofthe plunger 1, 5 but to limit liquid flow in the reverse direction.Since many conventional means are provided for these purposes, a furtherspecific description of suitable conventional metering means is notbelieved necessary.

The three sections 7, 9 and 11 of the door closer spring may be spacedfrom the door closer rod or shaft 14 by means of washers 8 which havepositioning tabs 15 struck therefrom or they may be positioned by otherequivalent is held'in place by a nut 4 threaded on the end of the shaftQ 14. The plunger assembly just described may be tightened down againsta steel pin Gextending from the shaft 14.

Between the end body portions 3 and 12 of the door separate theseextremes, and the door closer of the incloser assembly extends thehousing tube 17. A lock or detent '13 may be provided on the shaft 14,as shown. The shaft 14 may be pivotally attached at its end to a bracketwhich is mounted on the door to move with the door. The flange 3 may bepivotally attached to a etationary bracket mounted on the. framesurrounding the door. 5 w

The drawing shows on a reduced scale, but in proper porportion, theelements of a compressionspring door closetas this term is abpve definedin terms of the design criteria and spring characteristics called for inde-' vices of this type.

l The above description of the invention shouldmalreitapparent that somedetails of -the apparatus embodying theinvention may be varied withoutdeparting from the teaching of-the' invention. For exarnple, more thanthree spring sections may be provided, 'although this is not preferredbecause of higher costs. Accordingly, thescope of the invention is notto be limited to precise details of butis to be dedisposed within saidhousing and adapted toshiftbetween saidends and defining a fluid chamberadjacent said first end, fluidmetering means communicating withsaid-chamber for venting fluid therefrom when it'heplunger ap.- proachessaid first end, spring means extending between said plunger and saidsecond end to bias said plunger toward said first end, said spring meanshaving a ratio of overall free length to mean spring diameter pf from 12to 20 and havinga spring rate of 2 to 5, poundsper inch of deflectionand having a load 'ofpfro m 10 to 25pounds at a compressed length offrom 6 to 10 inches, a rod extending from said plunger through saidspring means and'out said second end, said spring means being dividedinto three sections, and means mountedron said rod between atple'astthree sections, andmeans mounted on said rod,

between eachadjacent pair of said-sections for holding the associatedends, of/said'pairs' in centeredrelationship;

each adiacent pair of said sections for holding the associated ends ofsaid pairs in centered relationship around said rod.

2. A compression spring door closer comprising a housing having a firstclosed end and a second end, a plunger disposed within said housing andadapted to shift between said ends and defining a fluid chamber adjacentsaid first end, fluid metering means communicating with said chamber forventing fluid therefrom when the plunger approaches said first end,spring means extending between said plunger and said second end to biassaid plunger toward said first end, said spring means having a ratio ofoverall free length to" mean spring diameter of from 12 to 20 and havinga spring rate of 2 to 5 pounds per inch of deflection and having a loadof from 10 to 25 pounds at a compressed length of from 6 to 10 inches, arod'extending from said plunger through said spring means and out saidsecond end, said springmeansbeing divided into around said'rodi s 7References Cited in file of thispatent V UNITED" sTATnsrnrENrs f71,743,360 Lang Ian}. 14, 1930 1,033,035 QKdons 1 ;Mar.3,1936

2,482,114 r Nixon Sept. 20, 1949

